KH600
DATA SHEET
Application Information
General Description
Standard Operation:
+V
b1
= +V
b2
= +V
s
= +5V;
-V
b
= -V
s
= -5V
The KH600 is a 1GHz differential input/output amplifier
constructed using Cadeka’s in-house thin film resistor/bipolar
transistor technology. A differential signal on the inputs of the
KH600 will generate a differential signal at the outputs. If a
single ended input signal is applied to IN1 and a fixed voltage
to IN2, the KH600 will produce both a differential and common-
mode output signal. To achieve the maximum dynamic range,
center the inputs halfway between +V
s
and -V
s
.
The KH600 includes 50Ω resistors from each input to ground,
resulting in a differential input impedance of 100Ω. Each
KH600 output has a 50Ω resistance, synthesized by feedback,
providing a 100Ω differential output impedance.
+V
s
+IN
C16
6.8µF
+
+V
b1
+V
s
C15
0.01µF
30pF
C1
0.01µF
+OUT
12
11
+V
b1
GND
+V
s
10
1
-V
b
C6
6.8µF
C5
0.01µF
2
3
+V
b2
GND
9
-V
b
U1
KH600
+V
s
-V
s
8
7
-V
s
+
C8
0.01µF
4
5
6
-IN
C13
0.01µF
30pF
C14
6.8µF
+
+V
b2
+V
s
GND
GND
-V
s
-V
s
+V
s
C4
0.01µF
-OUT
The KH600 has 3 bias voltage pins that can be used to:
• Adjust the supply current
• Trim the differential output offset voltage
• Adjust the common mode output offset voltage
over a ±3V range
If these adjustments are not required, short +V
b1
and +V
b2
to
+V
s
and -V
b
to -Vs as shown in Figure 2. Throughout this
data sheet, this configuration (+V
b1
= +V
b2
= +V
s
= +5V and
-V
b
= -V
s
= -5V) is referred to as the Standard Operating
Condition. All of the plots in the Typical Performance section
and the specifications in the Electrical Characteristics table
utilize the basic circuit configuration shown in Figure 2,
unless otherwise indicated. Figure 3 illustrates the optional
circuit configuration, utilizing the bias voltage pins. Further
discussions regarding these optional adjustments are provided
later in this document.
+V
s
C9
6.8µF
C10
6.8µF
Figure 3: Optional Circuit Configuration (including
optional supply current and offset adjust)
Gain
Differential Gain for the KH600 is defined as (OUT1– OUT2)/
(IN1–IN2). Applying identical (same phase) signals to both
inputs and measuring one output will provide the Common
Mode Gain. Figure 4 shows the differential and common
mode gains of the KH600. Figure 5 illustrates the response
of the KH600 outputs when one input is driven and the other
is terminated into 50Ω.
20
15
+IN
C1
0.01µF
+OUT
Differential Gain
Gain (dB)
+V
s
+V
s
GND
-V
s
-V
s
10
5
0
Common Mode Gain
12
11
+V
b1
-V
s
GND
+V
s
10
1
2
3
+V
b2
GND
9
-V
b
U1
KH600
+V
s
-V
s
8
7
-V
s
C6
0.01µF
C8
0.01µF
-5
C9
6.8µF
-OUT
C10
6.8µF
4
5
C4
0.01µF
-IN
+V
s
6
-10
1M
10M
100M
1G
Frequency (Hz)
Figure 2: Basic Circuit Configuration
Figure 4: Differential and Common Mode Gain
REV. 2 January 2004
7
CADEKA [ CADEKA MICROCIRCUITS LLC. ]
